Closure cap for liquid containers

A closure cap (1) for a liquid container, comprising

• a cap body (21), including
• a cover section (2),
• a screw collar (3) with an internal thread (5) for screwing onto an external thread (6) of the liquid container, the internal thread (5) having an internal thread diameter, and
• an inwardly projecting bulge projection (16) which runs at least in sections around an inner wall of the cap body (21), the inwardly projecting bulge projection (16) having a bulge diameter that is smaller than the internal thread diameter;
• and
• a functional insert (10) detachably fixed in the cap body (21) in a preassembled state before the closure cap (1) is screwed onto the liquid container, including
• a base section (14), and
• a latching web (15) which is arranged on the functional insert (10), is resilient in a radial direction, extends at least in sections radially outward and downward around the base section (14), and engages above the inwardly projecting bulge projection (16).